Union leader Dan McConnell helped wrangle backing from the Minneapolis City Council for a new Vikings stadium in one of its most contentious votes in recent history. Now, council members are trying to win support of their own from the DFL party he chairs.

The Minneapolis DFL’s endorsement could prove pivotal this year, with all 13 council seats up for grabs and an especially competitive mayor’s race that lacks an incumbent for the first time in two decades.

The twin roles of McConnell, who is also business manager of the Minneapolis Building and Construction Trades Council, don’t seem to trouble City Hall veterans. One noted that labor has been the “L’’ in the DFL Party for more than six decades. They are, nonetheless, a revealing example of the way that party politics and union influence continue to intersect at City Hall — in big votes and big elections.

McConnell, 42, acknowledged in an interview that he has a conflict of interest, but said the same is true of other players in Minnesota politics. And, he added, he does not expect the 7-6 council stadium vote to play much of a role in the DFL endorsement in June or the city campaigns next fall.

“I’ve gotten calls [from council members] saying: ‘I’ve heard you’re not going to endorse any of us if we didn’t vote for the stadium.’ And I told them: ‘That’s one vote, and it’s not the only vote that you’ve ever taken, and we’re going to look at you as a whole person,’ ” McConnell said.

The stadium, he said, is no longer an issue, and “maybe five people in the city haven’t moved on.”

The vote, though, had some political impact. Just a few months ago, dozens of union workers gathered for a fund­raiser hosted by the Trades Council and the Minneapolis Regional Labor Federation in honor of the seven council members who voted for the stadium. They praised them for supporting economic development. They made campaign contributions.

McConnell was also in the room that day thanking the officials for creating jobs.

Council Member Don Samuels, a stadium backer who attended, recalled feeling surprised at the show of union support because he had not previously enjoyed a close relationship with organized labor.

“I didn’t know that that could happen — that all the unions could get together like that, and I got an envelope with … a couple grand,” he said recently.

Last spring, the council approved a $309 million subsidy for a new stadium by diverting city sales taxes. While supporters touted the benefits of keeping the Vikings in Minneapolis and an accompanying provision to renovate Target Center, opponents voiced frustration that the council was overriding the municipal charter, which requires a referendum when the city spends more than $10 million on a professional sports facility.

Coalescing support

Advocates, including McConnell, spent months drumming up enough votes for the deal, which was considered vital to selling a larger stadium agreement at the Legislature. McCon­nell made his case to council members and had union members show up at community forums to show support.

Today, the Building and Construction Trades Council says it is endorsing all council members who voted for the stadium and are running for re-election: Diane Hofstede, Sandy Colvin Roy, Kevin Reich, Meg Tuthill, Barb Johnson and John Quincy. No endorsement has been made yet for the mayor’s race, in which Samuels is running.

“The fact that the six supported the stadium, we felt warranted early endorsement,” said David Ybarra, president of the Trades Council.

McConnell became business manager of the organization in 2011, two years after being voted DFL chair. The labor group has about 17,000 members working as carpenters, ironworkers, boilermakers, sprinkler fitters and other building and construction jobs. He has recused himself on union votes and screenings for political endorsements, and hopes that the Trades Council will wait to make its endorsements for the mayor’s race until after the DFL decides on the matter at the June convention.

“I have two roles and I think they’re distinct, and I try to keep them distinct,” he said. Still, he added, “I feel like people are watching me.”

City Council President Barb Johnson, who also attended the fundraiser, noted that labor is in the party’s name.